[autotest] add trybot support to ParseBuildName

Updates the ParseBuildName utility to accept trybot builds.

BUG=chromium:412451
TEST=able to create suite jobs with a trybot build in the afe.
DEPLOY=apache

Change-Id: Ie8664692280cbd811e7314468eaaa6248d8b6224
Reviewed-on: https://chromium-review.googlesource.com/217294
Reviewed-by: Dan Shi <dshi@chromium.org>
Reviewed-by: Simran Basi <sbasi@chromium.org>
Tested-by: Simran Basi <sbasi@chromium.org>
Commit-Queue: Simran Basi <sbasi@chromium.org>
diff --git a/server/site_utils.py b/server/site_utils.py
index 528a9a9..b0fa276 100644
--- a/server/site_utils.py
+++ b/server/site_utils.py
@@ -53,9 +53,10 @@
                       Will be None for relative build names.
 
     """
-    match = re.match(r'(?P<board>[\w-]+)-(?P<type>\w+)/(R(?P<milestone>\d+)-'
-                     r'(?P<manifest>[\d.ab-]+)|LATEST)', name)
-    if match and len(match.groups()) == 5:
+    match = re.match(r'(trybot-)?(?P<board>[\w-]+)-(?P<type>\w+)/'
+                     r'(R(?P<milestone>\d+)-(?P<manifest>[\d.ab-]+)|LATEST)',
+                     name)
+    if match and len(match.groups()) >= 5:
         return (match.group('board'), match.group('type'),
                 match.group('milestone'), match.group('manifest'))
     raise ParseBuildNameException('%s is a malformed build name.' % name)